/**
 * 
 */
package com.puneet.graphqueries.ssh;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.List;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

/**
 * @author puneet
 *
 */

/**
 * Utility class to carry out an upload scp transfer.
 */
public class ScpToMessage extends AbstractSshMessage {

	private static final int HUNDRED_KILOBYTES = 102400;
	private static final int BUFFER_SIZE = 1024;

	private File localFile;
	private String remotePath;
	private List directoryList;

	/**
	 * Constructor for ScpToMessage
	 * 
	 * @param session
	 *            the ssh session to use
	 */
	public ScpToMessage(Session session) {
		super(session);
	}

	/**
	 * Constructor for ScpToMessage
	 * 
	 * @param verbose
	 *            if true do verbose logging
	 * @param session
	 *            the ssh session to use
	 * @since Ant 1.7
	 */
	public ScpToMessage(boolean verbose, Session session) {
		super(verbose, session);
	}

	/**
	 * Constructor for a local file to remote.
	 * 
	 * @param verbose
	 *            if true do verbose logging
	 * @param session
	 *            the scp session to use
	 * @param aLocalFile
	 *            the local file
	 * @param aRemotePath
	 *            the remote path
	 * @since Ant 1.6.2
	 */
	public ScpToMessage(boolean verbose, Session session, File aLocalFile, String aRemotePath) {
		this(verbose, session, aRemotePath);

		this.localFile = aLocalFile;
	}

	/**
	 * Constructor for a local directories to remote.
	 * 
	 * @param verbose
	 *            if true do verbose logging
	 * @param session
	 *            the scp session to use
	 * @param aDirectoryList
	 *            a list of directories
	 * @param aRemotePath
	 *            the remote path
	 * @since Ant 1.6.2
	 */
	public ScpToMessage(boolean verbose, Session session, List aDirectoryList, String aRemotePath) {
		this(verbose, session, aRemotePath);

		this.directoryList = aDirectoryList;
	}

	/**
	 * Constructor for ScpToMessage.
	 * 
	 * @param verbose
	 *            if true do verbose logging
	 * @param session
	 *            the scp session to use
	 * @param aRemotePath
	 *            the remote path
	 * @since Ant 1.6.2
	 */
	private ScpToMessage(boolean verbose, Session session, String aRemotePath) {
		super(verbose, session);
		this.remotePath = aRemotePath;
	}

	/**
	 * Constructor for ScpToMessage.
	 * 
	 * @param session
	 *            the scp session to use
	 * @param aLocalFile
	 *            the local file
	 * @param aRemotePath
	 *            the remote path
	 */
	public ScpToMessage(Session session, File aLocalFile, String aRemotePath) {
		this(false, session, aLocalFile, aRemotePath);
	}

	/**
	 * Constructor for ScpToMessage.
	 * 
	 * @param session
	 *            the scp session to use
	 * @param aDirectoryList
	 *            a list of directories
	 * @param aRemotePath
	 *            the remote path
	 */
	public ScpToMessage(Session session, List aDirectoryList, String aRemotePath) {
		this(false, session, aDirectoryList, aRemotePath);
	}

	/**
	 * Carry out the transfer.
	 * 
	 * @throws IOException
	 *             on i/o errors
	 * @throws JSchException
	 *             on errors detected by scp
	 */
	public void execute() throws IOException, JSchException {
		if (directoryList != null) {
			doMultipleTransfer();
		}
		if (localFile != null) {
			doSingleTransfer();
		}

	}

	private void doSingleTransfer() throws IOException, JSchException {
		String cmd = "scp -t " + remotePath;
		Channel channel = openExecChannel(cmd);
		try {

			OutputStream out = channel.getOutputStream();
			InputStream in = channel.getInputStream();

			channel.connect();

			waitForAck(in);
			sendFileToRemote(localFile, in, out);
		} finally {
			if (channel != null) {
				channel.disconnect();
			}
		}
	}

	private void doMultipleTransfer() throws IOException, JSchException {
		Channel channel = openExecChannel("scp -r -d -t " + remotePath);
		try {
			OutputStream out = channel.getOutputStream();
			InputStream in = channel.getInputStream();

			channel.connect();

			waitForAck(in);
			for (Iterator i = directoryList.iterator(); i.hasNext();) {
				Directory current = (Directory) i.next();
				sendDirectory(current, in, out);
			}
		} finally {
			if (channel != null) {
				channel.disconnect();
			}
		}
	}

	private void sendDirectory(Directory current, InputStream in, OutputStream out) throws IOException {
		for (Iterator fileIt = current.filesIterator(); fileIt.hasNext();) {
			sendFileToRemote((File) fileIt.next(), in, out);
		}
		for (Iterator dirIt = current.directoryIterator(); dirIt.hasNext();) {
			Directory dir = (Directory) dirIt.next();
			sendDirectoryToRemote(dir, in, out);
		}
	}

	private void sendDirectoryToRemote(Directory directory, InputStream in, OutputStream out) throws IOException {
		String command = "D0755 0 ";
		command += directory.getDirectory().getName();
		command += "\n";

		out.write(command.getBytes());
		out.flush();

		waitForAck(in);
		sendDirectory(directory, in, out);
		out.write("E\n".getBytes());
		out.flush();
		waitForAck(in);
	}

	private void sendFileToRemote(File localFile, InputStream in, OutputStream out) throws IOException {
		// send "C0644 filesize filename", where filename should not include '/'
		long filesize = localFile.length();
		String command = "C0644 " + filesize + " ";
		command += localFile.getName();
		command += "\n";

		out.write(command.getBytes());
		out.flush();

		waitForAck(in);

		// send a content of lfile
		FileInputStream fis = new FileInputStream(localFile);
		byte[] buf = new byte[BUFFER_SIZE];
		long startTime = System.currentTimeMillis();
		long totalLength = 0;

		// only track progress for files larger than 100kb in verbose mode
		boolean trackProgress = getVerbose() && filesize > HUNDRED_KILOBYTES;
		// since filesize keeps on decreasing we have to store the
		// initial filesize
		long initFilesize = filesize;
		int percentTransmitted = 0;

		try {
			if (this.getVerbose()) {
				System.out.println("Sending: " + localFile.getName() + " : " + localFile.length());
			}
			while (true) {
				int len = fis.read(buf, 0, buf.length);
				if (len <= 0) {
					break;
				}
				out.write(buf, 0, len);
				totalLength += len;

				if (trackProgress) {
					percentTransmitted = trackProgress(initFilesize, totalLength, percentTransmitted);
				}
			}
			out.flush();
			sendAck(out);
			waitForAck(in);
		} finally {
			if (this.getVerbose()) {
				long endTime = System.currentTimeMillis();

			}
			fis.close();
		}
	}

	/**
	 * Get the local file
	 * 
	 * @return the local file
	 */
	public File getLocalFile() {
		return localFile;
	}

	/**
	 * Get the remote path
	 * 
	 * @return the remote path
	 */
	public String getRemotePath() {
		return remotePath;
	}
}
